Heat sink

ABSTRACT

A heat sink adapted for removing heat from a plurality of LEDs, includes a heat-conducting member, a plurality of conducting arms extending radially and outwardly from a periphery of the heat-conducting member and a plurality of outer fins perpendicularly extending from at least a lateral side of each of the conductive arms. The outer fins are spaced from and surround the heat-conducting member. Outer faces of outermost ones of the outer fins are used for thermal connection with the LEDs, whereby heat generated by the LEDs is absorbed by the heat sink. A plurality of spaces is defined between the outer fins, the heat-conducting member and the conducting arms and through bottom and top of the heat sink, whereby the heat absorbed by the heat sink can be easily dissipated to surrounding atmosphere along a vertical direction.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to heat sinks, and particularly to a heatsink for removing heat from electronic components such as LEDcomponents.

2. Description of related art

Electronic component includes numerous circuits operating at high speedand generating substantive heat. In many applications, it is desirableto employ a heat sink to remove heat from heat-generating electroniccomponents, for example, LED components in an LED lamp, to assure thatthe components function properly and reliably.

An LED lamp is a type of solid-state lighting device that utilizeslight-emitting diodes (LEDs) as a source of illumination. An LED is adevice for converting electricity into light by using a theory that, ifa current is made to flow in a forward direction through a junctionregion comprising two different types of semiconductor, electrons andholes are coupled at the junction region to generate a light beam. TheLED has an advantage that it is resistant to shock, and has an almosteternal lifetime under a specific condition; thus, the LED lamp isintended to be a cost-effective yet high quality replacement forincandescent and fluorescent lamps.

An LED lamp generally has a limited space therein and requires aplurality of LEDs. Most of the LEDs are driven at the same time, whichresults in a quick rise in temperature of the LED lamp. Since thelimited space in the LED lamp, the heat sink has a restricted heatdissipating area and is unable to remove heat from the LEDs effectively.Operation of the conventional LED lamps thus has a problem ofinstability because of the rapid buildup of heat.

What is needed, therefore, is a heat sink has a greater heat-transfercapability in a limited space.

SUMMARY OF THE INVENTION

A heat sink adapted for removing heat from a plurality ofheat-generating components, such as LEDs, includes a cylindricalheat-conducting member, a plurality of conducting arms extendingradially and outwardly from a periphery of the heat-conducting memberand a plurality of outer fins perpendicularly extending from two lateralsides of each of the conductive arms. The outer fins are spaced from andsurround the heat-conducting member. The outer fins has an outermost onewhich has an outer, flat surface adapted for thermally connecting withthe heat-generating components, whereby heat generated by theheat-generating components is absorbed and dissipated to surrounding airby the heat sink.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the present heat sink can be better understood withreference to the following drawings. The components in the drawings arenot necessarily drawn to scale, the emphasis instead being placed uponclearly illustrating the principles of the present LED lamp. Moreover,in the drawings, like reference numerals designate corresponding partsthroughout the several views.

FIG. 1 is an isometric view of a heat sink in accordance with apreferred embodiment of the present invention; and

FIG. 2 is a top view of the heat sink of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1-2, a heat sink is disclosed for removing heat fromheat-generating electronic components (not shown) such as LEDs in an LEDlamp.

The heat sink is integrally formed of a one-piece metal with good heatconductivity, such as aluminum or copper. The heat sink has aheat-conductive member at a center thereof. In this embodiment, theheat-conductive member is an elongated cylinder 10 with a through hole(not labeled) defined therein. The cylinder 10 has a plurality of innerfins 12 extending inwardly from an inner wall thereof. The inner fins 12are centrosymmetric relative to a central axis of the cylinder 10 andeach have a thickness gradually decreasing inwardly. The heat sink has aplurality of conducting arms 14 extending radially and outwardly from anouter wall of the cylinder 10. The conducting arms 14 are identical toeach other and centrosymmetric relative to the central axis of thecylinder 10. A quantity of the conducting arms 14 can be different in analternative embodiment. In this embodiment, the quantity of theconducting arms 14 is designed to be six. A plurality of pairs of outerfins 140 are formed on two opposite lateral sides of each of theconducting arms 14. Each pair of the outer fins 140 extend respectivelyand perpendicularly from the two opposite lateral sides of acorresponding conducting arm 14 and are symmetrical to each otherrelative to the corresponding conducting arm 14. Lengths of the outerfins 140 at a lateral side of each of the conducting arms 14 increasealong a direction from the cylinder 10 to a distal end of thecorresponding conducting arm 14. The distal end of the conducting arm 14terminates at an inner face of an outermost one of the outer fins 140.An outer face of each outermost outer fin 140 is flat and used forthermally contacting with the LEDs.

Heat generated by the LEDs is first received by the outermost ones ofthe outer fins 140. Then the heat is transferred to inner ones of theouter fins 140 and the elongated cylinder 10 and the inner fins 12 viathe conducting arms 14. The heat is dissipated to a plurality of spaces(not labeled) between the conducting arms 14, the outer fins 140, theelongated cylinder 10 and the inner fins 12, wherein the spaces extendvertically through the heat sink. Air in the spaces and heated by theheat from the LEDs flows upwardly beyond a top of the heat sink, wherebycool air enters into the spaces from a bottom of the heat sink.Therefore, the heat is taken away from the heat sink to the surroundingair so that the heat generated by the LEDs can be effectivelydissipated.

It is believed that the present invention and its advantages will beunderstood from the foregoing description, and it will be apparent thatvarious changes may be made thereto without departing from the spiritand scope of the invention or sacrificing all of its materialadvantages, the examples hereinbefore described merely being preferredor exemplary embodiments of the invention.

1. A heat sink adapted for removing heat from LEDs of an LED lamp, theheat sink comprising: a heat-conducting member; and a plurality of outerfins being spaced from and surrounding the heat-conductive member, theouter fins having outermost ones forming outer contacting faces adaptedfor contacting with the LEDs.
 2. The heat sink of claim 1, wherein eachof the contacting faces of the outermost ones of the outer fins is flat.3. The heat sink of claim 1, wherein the heat-conducting member is acylinder with a through hole defined therein.
 4. The heat sink of claim3, wherein the cylinder has a plurality of inner fins extending inwardlyfrom an inner wall thereof.
 5. The heat sink of claim 4, wherein athickness of each of the inner fins decreases gradually from the innerwall of the cylinder to a distal end of the each of the inner fins. 6.The heat sink of claim 1, wherein a plurality of conducting arms extendoutwardly from an outer wall of the cylinder, and the outer fins extendfrom two lateral sides of each of the conducting arms.
 7. The heat sinkof claim 6, wherein the conducting arms radially and evenly extend fromthe outer wall of the cylinder.
 8. The heat sink of claim 7, wherein theconducting arms are centrosymmetric relative to a central axis of thecylinder.
 9. The heat sink of claim 8, wherein the outer fins areperpendicular to a corresponding conducting arm from which the outerfins are extended, and the outer fins which extend from thecorresponding conducting arm are divided into a plurality of pairs eachbeing symmetrical to the corresponding conducting arm.
 10. The heat sinkof claim 6, wherein lengths of the outer fins extending from each of theconducting arms are gradually increased along a direction from theheat-conducting member to a distal end of a corresponding conductingarm.
 11. The heat sink of claim 10, wherein the distal end of thecorresponding conducting arm terminates at an inner face of acorresponding outermost one of corresponding outer fins, the inner facebeing opposite to the contacting face of the corresponding outermost oneof the corresponding outer fins.
 12. A heat sink adapted for removingheat from a plurality of heat-generating components comprising: aheat-conducting member; a plurality of conducting arms extendingradially and outwardly from a periphery of the heat-conducting member;and a plurality of outer fins perpendicularly extending from at least alateral side of the conductive arm, the outer fins spaced from andsurrounding the heat-conducting member; wherein outer faces of outermostones of the outer fins are adapted for contacting with theheat-generating components.
 13. The heat sink of claim 12, wherein theheat-conducting member is a cylinder with a through hole definedtherein, a plurality of inner fins extending inwardly from an inner wallof the cylinder.
 14. The heat sink of claim 13, wherein the inner finsare centrosymmetric relative to a central axis of the cylinder andthicknesses of the inner fins decrease inwardly.
 15. The heat sink ofclaim 12, wherein the conducting arms are centrosymmetric relative to acentral axis of the cylinder, the outer fins are formed at two lateralsides of each of the conductive arms.
 16. The heat sink of claim 15,wherein lengths of the outer fins are increased outwardly from thecylinder to distal ends of the conducting arms.
 17. The heat sink ofclaim 16, wherein each distal end of the conducting arms terminates atan inner face of an outermost one of corresponding outer fins, and anouter face of the outermost one of the corresponding outer fins is flatadapted for contacting with the electronic components.
 18. A heat sinkadapted for cooling LEDs, comprising: a tube-shaped heat conductivemember; a plurality of arms extending outwardly from an outer side ofthe heat conductive member; a plurality of outer fins connected to outerends of the arms, respectively, each outer fin having a flat outersurface adapted for thermally connecting with the LEDs; wherein aplurality of spaces is defined between the heat conductive member, thearms and the outer fins and extends through top and bottom of the heatsink.
 19. The heat sink of claim 18 further comprising a plurality ofadditional outer fins extending from the arms and located between theouter fins and the heat conductive member.
 20. The heat sink of claim 19further comprising a plurality of inner fins extending inwardly from aninner side of the heat conductive member.